Eley-Rideal and hot-atom reactions of H(D) atoms with D(H)-covered Cu(111)surfaces; quasiclassical studies

Quasiclassical molecular dynamics studies are made of H or D atoms incident from the gas phase onto D or H- covered Cu(111) surfaces. Two detailed mod el potential energy surfaces are used, both based on the results of extensi ve total energy calculations using the density functional method. The incid ent H (D) atoms can react directly to form HD via the Eley-Rideal mechanism , or trap onto the surface. These trapped hot atoms can react with the adso rbates to form HD or can eventually dissipate enough energy through collisi ons with the adsorbates to become immobile. We also observe the formation o f D-2 (H-2). Probabilities for these various processes, as well as the rota tional, vibrational, and translational energy distributions of the products are computed and compared with experiment. Hot-atom pathways to product fo rmation are shown to make significant contributions. One of the potentials gives excellent agreement with experiment, while the other is less successf ul. (C) 1999 American Institute of Physics. [S0021-9606(99)70522-2].